1. Field of the Invention
This invention relates to a retaining method for a spherical bearing, in particular, retaining an outer race on the portion to be retained.
2. Related Art
In general, in the spherical bearing, as shown in FIG. 10, it is constituted in such a manner as an inner race 51 having a sphere is made to be supported by an outer race 52 rotatably and slidably, the outer race 52 is made to be retained with a race retention 54 formed on a housing 53, snap rings 56 are made to be retained respectively with annular grooves 55 formed on the race hole 54 at a given spacing and the outer race 52 is retained with a housing 53 by making an end face 52a of the outer race 52 to be engaged with a pair of snap rings 56.
However, a pair of annular retaining grooves 55 to be retained with the snap rings 56 are formed by a machinery working on a wall face 54a of the race retention hole 54 and since, from an assembling view point, a clearance of the spacing of a pair of annular grooves 55 are set in plus, in such spherical bearing 57 as being mounted on the housing 53, as shown in FIG. 11, a gap is generated between the snap ring 56 and the end face 52a of the outer race 52 and due to an axial load entering the outer race 52, it has happened to be displaced between a pair of snap rings 56. And, in the case where such spherical bearing 57 is used in a steering drive system of the vehicle, the end face 52a of the outer race 52 is apt to hit the end face 56a of the snap ring 56 and the vibration generated is transmitted to the cavity of the vehicle through a frame to generate an unpleasant noise.
So that, as shown in FIG. 12, although it has been conventionally known, so-called, as a staking method for a retaining method, in which, at the opening of the race retention hole 54, chamfer portions 58 are formed and the peripheral surfaces 52b of the outer race 52 are formed with hook portions 59 to engage with the chamfers 58 for preventing the outer race from being displaced due to the axial load, a tight retention has been secured but on the other hand, processing of parts has been complicated to increase manufacturing cost.
The present invention has been made in the light of the above circumstance, and the object thereof is to provide a secure retention method for an outer race of a spherical bearing while controlling manufacturing cost.
In order to attain the above object, according to a first aspect of the present invention, in a retention method of a spherical bearing At consisting of an outer race and an inner race the spherical surface of which is supported on the outer race rotatably and slidably, in which the spherical bearing is retained with a race retention hole formed on a portion to be retained, on one side of an inner wall surface of the race retention hole of the portion to be retained a screw portion having a given stroke is formed coaxially with the race retention hole, on other side of the inner wall surface of the race retention hole an annular groove to be retained with a snap ring is formed, on one side of the periphery of the outer race a stepped portion having a diameter smaller than the diameter of the periphery is formed, in the state where the outer race of the spherical bearing is retained with the race retention hole a first snap ring is retained with the annular groove, and in the screw portion a setscrew formed with a through hole in an axial direction is screwed, tightened and pressured an end face of the stepped portion by a end face of the setscrew toward the first snap ring, thereby the first snap ring and the setscrew clamp the outer race to retain the spherical bearing to the portion to be retained.
Being structured as such, by retaining the first snap ring with the other side of the inner wall surface of the race retention hole, screwing and tightening the setscrew in the screw portion formed on the one side of the inner wall surface of the race retention hole, the end face of the setscrew pressures the end face of the stepped portion of the outer race toward the first snap ring, thereby the outer race is clamped by the setscrew and the first snap ring to retain the outer race on the portion to be retained.
According to a second aspect of the present invention, on the inner wall surface of the through hole of the setscrew, an annular groove is formed to be retained with a second snap ring.
Being structured as such, by abutting the end face of the second snap ring to the end face of the outer race, the outer race is retained on the portion to be retained more securely, further, by employing a high tensile spring as the second snap ring, a contact surface pressure between the setscrew and the screw portion is increased to prevent the setscrew from being loosened.
According to a third aspect of the present invention, on the U inner wall of the through hole of the setscrew an abutting portion to abut to one end face of the outer race is provided.
Being structured as such, by abutting the abutting portion formed on the setscrew to the end face of the outer race, the displacement of the outer race in axial direction is limited and can omit the second snap ring in the second aspect to reduce the number of the parts and the assembling processes.